* {
  margin: 0;
  padding: 0;
}
body {
  overflow: hidden;
}
.box {
  width: 300px;
  height: 300px;
  margin: 0 auto;
  margin-top: 100px;
  /* 变形 */
  transform: rotate(-45deg);
  position: relative;
}
.box .item {
  width: 100%;
  height: 100%;
  background: pink;
  /* border-radius:左上角 右上角  右下角 左下角 */
  border-radius: 300px 0px 300px 0px;
  position: absolute;
  left: 0;
  top: 0;
  /* 改变旋转原点 */
  transform-origin: left bottom;
  opacity: 0.8;
  /* 过渡 */
  transition: all 1s;
}
.box:hover .item:nth-child(1) {
  transform: rotate(-90deg);
}
.box:hover .item:nth-child(2) {
  transform: rotate(-60deg);
}
.box:hover .item:nth-child(3) {
  transform: rotate(-30deg);
}
.box:hover .item:nth-child(4) {
  transform: rotate(0deg);
}
.box:hover .item:nth-child(5) {
  transform: rotate(30deg);
}
.box:hover .item:nth-child(6) {
  transform: rotate(60deg);
}
.box:hover .item:nth-child(7) {
  transform: rotate(90deg);
}
